Robert ltjndell



(No Model.)

B. LUNDELL. GOMMUTATOR CYLINDER AND METHOD OF MAKING THE SAME. No.459,368.

Patented Sept. 8, 1891.

l vi tneooao $0M W & M

ZZMSAQ I UNITED STATES ROBERT LUNDE'LL, on NEW YORK, N. Y.,

PATENT OFFICE...

ASSIGNOR OF ONE-HALF TO EDIVARD II. JOHNSON, OF SAME PLACE.

SPECIFICATION forming part of Letters Patent No. 459,868, datedSeptember 8, 1891. Application filed April 4, 1891. serial No. 387,607.(No model.)

To all whom it may concern.-

Be it known that I, ROBERT LUNDELL, a citizen of the United States,residing at New York city, in the county and State of New York, haveinvented a certain new and useful Improvement in Oommutator-Oylinders,(Case D,) of which the following is a specification.

The present invention relates to commutator-cylinders and to the mode ofmaking them; and the main objects are to provide a commutator whichshall be strong and shall retain an even bearing-surface for thecommutator brushes and which shall be easy to manufacture; and theinvention consists in the several combinations hereinafter described andclaimed, and in the improved mode of forming the com mutator-eylinder.

. In the accompanying drawings, Figure 1 is an end View of thecommutator. Fig. 2 is a cross-section 011 line 00 x of Fig. 1, lookingin the direction of the arrow. Fig. 3 is asection of a modified form,and Fig. 4. is a section through a commutator and a holder and isdesigned to illustrate the mode of forming the cylinder.

In commutators which have heretofore been made by arrangingconducting-segments alternately with insulating segments or strips andsupporting the cylinder thus formed on the motor-shaft by means ofinterposed i11- sulating material the construction has been such thatthe strain incident to use of the commutator has caused the segments towork loose slightly and to thereby give an untrue bearing-surface forthe brushes. The effectof this is to cause sparking and consequentinjury to the brushes and t0 the segments. The Weakness of the oldcomnmtator-cylinders was due partly to the form of segments and partlyto the fact that all the force of the strain on any particular segmentcame directly on a small portion of the insulating material. I providean improved arrangement by which the objections mentioned are overcome.

In making my commutator I first form a suitable number ofconducting-segments 1, preferably of the shape shown in Fig. 2. If alarge number of segments are to be used, they are made of comparativelythin metal and are stamped; but if the segments are large, as indicatedin Fig. 1, they may be cast. I also form sections 2 of insulatingmaterial, preferably mica, which are the same shape as the metalsegments, but are slightly larger. This is indicated at the upper partof Fig. 2, where the outline of a metal segment is dotted behind theinsulating-plate 2. It is also indicated in Fig. 1, in whichtheinsulating-sections are shown as wider than the metal segments.

It will be seen that both the metal and insulating sections or segmentsare substantially H-shaped, there being a notch or slot 3 in each side.\Vhen the sections are put together, therefore, in the form of a ring orcylinder, two annular grooves are formed by said notches, one at eachend of the cylinder.

hen the segments are placed together as just described, I place the ringor cylinder with one end resting in the enlarged upper end of the holderor former 4:, and then by suitable means force the cylinder down intosaid holder. This, on account of the beveled face 5, presses the metaland insulating segments of the cylinder compactly together. I then placeat the center of the holder a spindle 6, equal in size to themotor-shaft with which the commutator-cylinder is to be used and havingat its lower end a round plate or disk 7,. with a beveled edge adaptedto fit the corresponding edge 5 of the holder. Over the spindle I placea metal sleeve 8, the surface of which is preferably inclined in twodirections, as shown. Having thus arranged the several parts, I pourinto the annular space i) a suitable insulating material, which, oncooling or drying, becomes hard. This material, unless it is very thin,will not entirely fill the space, but at the bottom will stopapproximately at the line 10. Before the insulating material becomeshardened a metal ring 11, which may have a flange 12, is driven into it,so that the ring is embedded in the insulating material within theannular groove heretofore described. The ring may be put in place beforethe upper part of the space 9 is entirely filled with insulatingmaterial, and then. insulating material may be put above the ring. Thisarrangement is indicated in Fig. 3. The next step in the mode of makingthe cylinder is to remove the spindle 6 and plate 7 and to insert thesame from the opposite end of the holder, inverting said holder andcylinder, and then to fill the annular space 9 with insulating materialand to embed a second ring 11. The cylinder is then removed from theholder, put into a lathe, and turned down to give it a perfectly smoothand even bearing-surface for the commutatorbrushes.

The modification illustrated in Fig. 3 differs from that alreadydescribed, in that the segments 1 2 have only one notch each, andconsequently the cylinder has but one annular groove for the receptionof the insulating material and for the reception of a strengthening-ring11. The mode of making it is the same as above described, except that itis unnecessary to reverse the cylinder to introduce insulating materialfrom both ends. The holder would also require to be of slightlydifferent shape to accommodate the flange formed by the projections 13,and the commutator cylinder would necessarily be inserted into the ringfrom the same side as the end disk 7.

14 is the shaft of a motor on which the commutator is to be used.

\Vith the construction described it is practically impossible for anyone of the segmenis to work loose and get out of line with the othersegments, since the ring or rings 11 are so embedded in the insulatingmaterial that any strain which would tend to move a segment of thecommutator or to cause it to work loose is not borne by the insulatingmaterial alone, but is borne by said rings. The faces 15 15 of theannular grooves are parallel with the faces of the ring or rings. Bymaking the insulating-sections larger than the conducting-sections it isrendered impossible for the metal rings to be so placed as to touch theconducting-segments.

that I claim is 1. A commutator-cylinder composed of alternateconducting and insulating sections, a filling of insulating materialbetween the cylinder and a sleeve or shaft on which it is mounted, and astrengthening-ring embedded in said insulating material, substantiallyas described.

2. A commutator-cylinder composed of alternate conducting and insulatingsections, the latter being wider than the former and projecting towardthe center, a filling of insulating material between the cylinder and asleeve or shaft on which it is mounted, and a metal ring embedded insaid insulating material, substantially as described.

3. A commutator-cylinder composed of alternate conducting and insulatingsections, a filling of insulating material between the cylinder and asleeve or shaft on which it is mounted, and two strengthening-ringsembedded in said insulating material, one at each end of the cylinder,substantially as described.

at. A commutator-cylinder composed of alternate conducting andinsulating sections, said sections being formed with one or morenotches, whereby when the cylinder is built up one or more annulargrooves are formed, a filling of insulating material bet w een th ecylinder and a sleeve or shaft on which lil lb mounted, and a ring orrings embedded in the insulating material and extending into said grooveor grooves, substantially as described.

5. A commutator-cylinder composed of alternate conducting and insulatingsections, said sections being formed with one or more notches withstraight sides, whereby when the cylinder is built up one or moreannular grooves with straight bearing faces are formed, a filling ofinsulating material be tween the cylinder and a sleeve or shaft on whichit is mounted, and a ring or rings embedded in theinsulating materialand exten ding into said groove orgrooves, substantially as described.

6. A commutator-cylinder composed of alternate conducting and insulatingH-shaped pieces, a central sleeve adapted to be mounted on a shaft, aninterposed filling of insulating material, and strengthening-ringsembedded in the insulating material, substantlally as described.

7. The combination, in a commutator, of a series of conducting andinsulating sections arranged to form a cylinder, at sleeve'or shaft onwhich the cylinder is mounted, insulating material between the cylinderand sleeve or shaft, and a strengthening-ring in the insulatingmaterial, substantially as described.

8. A holder or former for use in the manufacture of commutators,consisting of a ring or cylinder the internal diameter of which is equalto the diameter of the commutator-cylinder to be made, open at both endsand beveled, in combination with a beveled plate or disk having acentral stud adapted to fit in either end of the holder, substantiallyas described.

9. A holder for use in the manufacture of commutators, consisting of aring or cylinder the internal diameter of which is equal to the diameterof the commutator to be made, said ring having an open beveled end, incombination with a central stud or spindle supported by a bottom plate,substantially as described.

10. The improvement in the mode of making commutator-cylinders, whichconsists in assembling conducting and insulating sections alternately toform a cylinder, pressing said parts together by forcing them into asuitable holder, placing a sleeve or stud at the center of the cylinder,pouring a soft insulating material into the space between the cylinderand sleeve, and then forcing a strengthening-ring into said insulatingmaterial, substantially as described.

11. The improvement in the mode of making commutators, which consists inassem- IIO bling conducting and insulating sections alternately to forma ring or cylinder, pressing said parts together by forcing them into asuitable holder, placing a sleeve or stud at the center of the ring,pouring a soft insulating material into the space between the ring andsleeve at one end, forcing a strengtheningring into said insulatingmaterial, reversing the cylinder and filling the other end withinsulating material, and forcing in a see- IO 0nd strengthening-ring,substantially as described.

This specification signed and witnessed this 28th day or March, 1891.

ROBERT LUNDELL. lVitnesses:

CHARLES M. CATLIN, AUGS. HAVILAND.

